Embodiments of the invention relate generally to power converters and more specifically to system and method for operating a power converter such as a direct current (DC) to DC power converter or a DC to alternating current (AC) power converter.
DC to DC power converters are very prevalent in today's power system. There are many applications of DC to DC converters, e.g., power supplies for cell phones, laptops etc. Even in hybrid electric vehicles or military/civil aircrafts DC to DC converters may be used. For offshore applications, such as marine, there are variety of loads which may be fed by DC power supply. In such marine ships, many DC buses which are interconnected so as to transfer power therebetween may be utilized. The interconnections between DC buses require coupling the DC buses with DC to DC converters. Generally, the efficiency of the overall marine power architecture needs to be high which in turn requires highly efficient DC to DC converters. Thus, in many embodiments, soft switching is employed for controlling DC to DC converters. Soft switching of DC to DC converters reduces switching losses of the DC to DC converters.
In marine ships, where the power requirements are high, the DC to DC converters may need to be operated at high voltages. Since the DC to DC converters need to be operated at high voltages, in many embodiments, a plurality of series connected semiconductor devices are utilized. With the large number of semiconductor devices in series and their associated snubber circuit, conventional control method will lead to loss of soft switching during transient conditions and lower converter efficiency.
Therefore, it is desirable to provide a system and a method that will address the foregoing issues.